A process of manufacturing semiconductor substrates (hereinafter, simply referred to as “substrates”) conventionally involves various types of processing that is performed on substrates. For example, chemical solution processing such as etching is performed on a surface of a substrate having a resist pattern on its surface by supplying a chemical solution to the substrate. After the chemical solution processing ends, cleaning processing is performed by supplying a cleaning liquid to the substrate, and then dry processing is performed on the substrate.
In a substrate cleaning device disclosed in Japanese Patent Publication No. 3621568 (Document 1), a cover member is placed on a spin chuck that holds a wafer horizontally, and rotated along with the wafer. When performing cleaning processing on the substrate, first a cleaning liquid is supplied from an upper nozzle disposed above and spaced from the cover member to the substrate that is being rotated, through an opening provided in the cover member at the center of rotation. Examples of cleaning liquids that are used include hydrofluoric acid, hydrochloric acid, sulfuric acid, phosphoric acid, ammonia, and a hydrogen peroxide solution. Then, deionized water is supplied from the upper nozzle to the rotating substrate to wash away the cleaning liquid adhering to the substrate. When subsequently performing dry processing on the substrate, a nitrogen (N2) gas is ejected from the upper nozzle and supplied to the wafer through the opening of the cover member. This reduces the oxygen concentration in the space between the cover member and the wafer and accelerates drying of the substrate.
Similarly, in a substrate periphery processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2014.30045 (Document 2), a barrier plate is placed on a spin chuck that holds a wafer horizontally, and rotated along with the wafer. The barrier plate has a through hole in the center, and a flange pipe having an internal space communicating with the through hole is coupled to the upper surface of the barrier plate. A barrier plate flange having a through hole in the center is coupled to the upper end of the flange pipe. When the barrier plate is retracted from above the spin chuck, a barrier-plate hand moves upward to hold the barrier plate flange from below and further moves upward to separate the barrier plate above the spin chuck.
In the internal space of the flange pipe, a central-axis nozzle is disposed without being in contact with the flange pipe. When the wafer is processed, a process gas such as a nitrogen gas is supplied through the central-axis nozzle to the space between the barrier plate and the wafer. A barrier-side labyrinth member is fixed to the upper surface of the barrier plate flange, and above the barrier-side labyrinth member, a nozzle-side labyrinth member is disposed without being in contact with the barrier-side labyrinth member. The nozzle-side labyrinth member is fixed to a nozzle holder that holds the central-axis nozzle, and moves up and down along with the central-axis nozzle and the nozzle holder. A seal gas such as dry air is supplied to the space between the nozzle-side labyrinth member and the barrier-side labyrinth member.
In the substrate cleaning device of Document 1, the atmosphere outside the space between the cover member and the wafer may enter the space from the opening of the cover member. On the other hand, in the substrate periphery processing apparatus of Document 2, the seal gas supplied to the space between the barrier-side labyrinth member and the nozzle-side labyrinth member suppresses the entry of the atmosphere outside the space between the barrier plate and the wafer into the space from the through hole of the barrier plate. However, the configuration in which the barrier-side labyrinth member is fixed to the upper surface of the barrier plate flange and the nozzle-side labyrinth member is disposed above the barrier-side labyrinth member increases the size of the substrate periphery processing apparatus in the up-down direction. Moreover, if the pressure in the space between the barrier plate and the wafer varies and becomes lower than the external pressure, the sealing between the labyrinths may be broken and the external atmosphere may enter the space.